2-substituted pyridine derivatives and synthesis thereof

ABSTRACT

2-( Beta -(N-acylhomopiperazino) pyridines, the new compound, as well as their salts of pharmacologically acceptable acids and the synthesis thereof. The compounds possess excellent antalgic, anti-phlogistic and anti-edematous effects with low toxicity and so are suitable as medicament. They are orally or parenterally administered to the patients.

United States Patent Takahashi et al.

Z-SUBSTITUTED PYRIDINE DERIVATIVES AND SYNTHESIS THEREOF Inventors: Tohru Takahashi; Hachiro Sugimoto; Koichiro Ueda, all of Tokyo, Japan Filed: Nov. 11, 1971 Appl. No.: 197,937

Foreign Application Priority Data July 16, 197i Japan 46/524l2 US. Cl 260/240 J, 424/263, 260/294.8 R, 260/295 R, 260/296 R Int. Cl C07d 31/44 Field of Search 260/240 J, 295 R, 260/294.8 R, 239 BC, 268 H, 268 C [56] References Cited UNITED STATES PATENTS 3,098,066 7/l963 Mull 260/239 BC 3,448,192 6/1969 Mauvemay 260/268 H X 3,511,840 5/1970 Tesoro 260/239 BC X Primary Examiner-John D. Randolph Att0rneyE. F. Wenderoth, Michael R. Davis et al.

[57] ABSTRACT 2-[B-(N-acylhomopiperazino) pyridines, the new compound, as well as their salts of pharmacologically acceptable acids and the synthesis thereof. The compounds possess excellent antalgic, anti-phlogistic and anti-edematous effects with low toxicity and so are suitable as medicament. They are orally or parenterally administered to the patients.

9 Claims, No Drawings Z-SUBSTITUTED PYRIDINE DERIVATIVES AND SYNTHESIS THEREOF This invention relates to the new 2-substituted pyridine derivatives useful as medicament. More particularly, the present invention concerns with Z-[B-(N- acylhomopiperazino)ethyl]pyridines represented by the formula wherein R R and R are respectively hydrogen atom or a substituent selected from the group consisting of halogen, methyl, methoxy, nitro and methane-fulfonyl and A represents a direct union or vinylene bridge; as well as their salts of pharmacologically acceptable acids and synthetic preparation thereof.

It has been found that the new compounds of the aforementioned formula (I) and salts thereof exhibit various pharmacological activities and among others excellent antalgic, anti-phlogistic and anti-edematous effects.

As the pharmacologically acceptable acid salts of the compounds reprented by the formula (I), there may be mentioned their mineral acid salts such as hydrochloride, sulfate and nitrate as well as their organic acid salts such as tartrate, citrate, succinate and methanesulfonate.

Outstanding anti-edematous effect of {B-[N-(p-chlorocinnamoyl)homopiperazino]ethyl} pyridine hydrochloride, the compound (I) which is within the coverage of the aforementioned general formula (I), wherein R is p-Cl, R and R are hydrogen and A is vinylene bridge, CH=CH, hasbeen observed in the test on rats, wherein edema was induced by the injection of carrageenin. The anti-edematous effect of the compound (I') was evaluated in comparison with that of aspirin, the latter having been usually employed as standard for evaluation of anti-phlogistic and anti-edematous effects represented by a substance under test. The aqueous suspensions of the compound (I') and of aspirin in the amounts given in the hereinundermentioned Table were prepared by suspending them in a 5 percent aqueous solution of gum arabic. The suspensions were orally administered to the rats one our before the carrageenin injection.

As control, the 5 percent aqueous solution of gum arabic alone was also administered to another group of rats.

The results observed are given in Table.

TABLE Anti-edematous effect (Growth-inhibition of edema caused by carrageemn) Compound Oral dose of Oral dose of under Test 20 mg/kg b.w. 100 mg/kg b.w. Aspirin: almost nothing 25 Compound (I): 2i 46 Control (only with the 5% 0 0 gum arabic a.q. soln) The figures in Table respectively show the levels in per cent of anti-edematous effects of the compounds as compared with that of the control.

From the Figures, it is seen that even though the oral administration of such a small amount of the compound (l'), there was obtained an appreciable antiedematous effect and furthermore that with the oral administration of mg/kg b.w. of said compound, there was obtained approximately twice inhibition effect of that of aspirin.

Incidentally, it was known that administration of aspirin is liable to cause serious side-effect on the digestive organs and that such side-effect is particularly enhanced when an excess amount is administered for an elongated period of time to cause gastritis which occasionally leads to gastric ulcer,

In contrast to the above, it has been found that administration of the compounds of the present invention do not cause any injurious side-effect on digestive organs.

It was further found that the compounds of the present invention did not show any serious side-effect on central nervous system, contrary to phenylbutazone and indomethacine, for example, which at present are broadly employed as anti-phlogistic and antiedematous agents.

The compounds of the present invention may be provided in a form of powdery and liquid medicines, tablets and capsules for oral administration and in a form of parenteral administration such as ampoules for injection and suppository.

It was found that 50-150 mg/day of the compounds of the present invention may orally be administered without any serious side-effect. Of course, the amount of dose may be altered depending-upon the symptom of dieseases to be treated.

As is explained in the above, the primary object of the present invention is to provide a useful medicament possessing excellent anti-phlogistic and anti-edematous effects without any serious side-effect.

The chemical reaction which takes place in carrying out the synthetic preparation of the particular compounds according to the present invention may be explained by the following schematic chemical equation:

It; (III) contemplated compound (I). The reaction can smoothly be effected in the presence ofan alkaline condensing agent such as caustic alkali, alkali bicarbonate, triethylamine, etc. The resulting reaction product recovered from the reaction mixture may be purified by recrystallization from a conventional organic solvent such as methanol, ethanol, isopropanol, ether and acetone as well as a mixture thereof.

The resulting product, if desired, may be converted into salt by treating it with a pharmacologically acceptable inorganic or organic acid in accordance with a usual manner.

The following Examples will serve to illustrate the invention.

1 EXAMPLE 1 Synthetic preparation I of 2- {13. [N-(o-chlorobenzoyl)homopiperazi nolethyl} pyridine To 40 ml of an acetone solution containing 3.5 grams (0.02 mol.) of o-chlorobenzoyl chloride and l gram of potassium bicarbonate were added drop by drop with stirring under ice-cooling 20 ml of an acetone solution which contained 4.1 grams (0.02 mol.) of Z-(B- homopiperazinoethyl)pyridine. When the addition was over, the whole was refluxed on a boiling water bath for about 2 hours to complete the reaction. After removal of a minute amount of the solid substances essentially consisting of potassium chloride separated out in the reaction system was removed by filtration, and the filtrate was evaporated out. The residue was again dissolved in 50 ml of dry acetone and sufficient quantity of dry hydrogen chloride was passed through the solution in order to convert the basic product into hydrochloride thereof. The acetone was stripped out and the residue was recrystallized from a mixture of isopropano! and ether. There was thus obtained the hydrochloride having the melting point of 183186C. Yield of the product was 5.7 grams corresponding to 75.2 percent of the theory.

Elementary analysis -of the product as C H CIN OHCI gave:

C H N Found (96): 59.97 6.19 11.30 Calculated (75): 59.55 6.11 11.05

EXAMPLE 2 Synthetic preparation of 2- B-[N-(p-chlorocinnamoyi)homopiperazino1ethyl} pyridine 3.3 Grams (0.017 mol.) of p-chlorocinnamoyl chloride and 3.1 grams (0.015 mol.) of 2-(5- homopiperazinoethyl)-pyridine were subjected to reaction and the reaction product was further worked up in accordance with the procedures disclosed in Example 1. Crude hydrochloride of the product was recrystallized from a mixture of isopropanol and methanol. 5.2 Grams of the purified product having the melting point of 192-l94C. were thus obtained. Yield of the product was 81.3 perecnt of the theory.

Elementary analysis of the product as C H ClN O-Hcl gave:

Found (91:): 61.77 6.20 10.16

Calcualted (16): 62.06 6.21 10.34

EXAMPLE 3 Elementary analysis of the product as C l-l N sO 'l lCl gave:

C H N Found (16): 56.38 6.17 10.08 Calculated (96): 56.65 6.19 9.91

EXAMPLE 4 Synthetic preparation of 2- B-[N-(3,S-dichlorobenzoyl)homopiperazino1ethyl pyridine 3 ,S-Dichlorobenzoyl chloride and 2-( B- homopiperazinoethyl)pyridine in equimolar proportions were subjected to reaction and the reaction product was further worked up in accordance with the manners disclosed in Example 1. There was obtained the contemplated compound as hydrochloride thereof having the melting point of 168-170C.

Elementary analysis of the product as C,,H ,Cl N O'HCl%H 0 gave:

C H N Found 54.31 5.61 10.18 Calculated (96): 54.10 5.43 9.93

, EXAMPLE 5 Synthetic preparation of 2- B-[N-(o-methylbenzoyl)homopiperazino1ethyl pyridine o-Methylbenzoyl chloride and 2-()3-homopiperazino ethyl)-pyridine in equirnolar proportions were subjected to the reaction and the reaction product was further worked up in accordance with the manner disclosed in Example 1.

There was obtained the contemplated product as hydrochloride having the melting point of l87-189CL Elementary analysis of the resulting product as C H N O'l-ICl gave:

Found (96): 66.37 7.28 11.67

Calculated 66.73 7.30 11.68

EXAMPLE 6 Synthetic preparation of 2- B-[ N-( 3 ,4 ,5 -trimethoxybenzoyl homopiperazino1ethyl pyridine 3,4,5-Trimethoxybenzoyl chloride and 2-(3- homopiperazinoethyl)pyridine in equirnolar proportions were subjected to reaction and the reaction product was further worked up in accordance with the procedures disclosed in Example 1.

There was obtained the contemplated compound as hydrochloride having the melting point of 17 l 173C.

Elementary analysis of the product as CzzHggNgOfHCl gave:

C H N Found 60.01 7.15 9.70 Calculated 60.60 6.95 9.64

EXAMPLE 7 Synthetic preparation of 2- C H N Found 67.33 7.11 11.47 Calculated 67.81 7.06 11.30

EXAMPLE 8 Synthetic preparation of 2- fi-[N-(p-nitrobenzoyl)homopiperazino1-ethyl} pyridine p-Nitrobenzoyl chloride and 2-(B-homopiperazinoethyl)-pyridine in equimolar proportions were subjected to reaction and the resulting reaction product was further worked up in accordance with the procedures disclosed in Example 1.

There was obtained the contemplated product as hydrochloride having the melting point of 203-205C.

Elementary analysis of the product as C l-l N O 'HClrH 0 gave:

C H N Found 57.30 5.87 14.33 Calculated 57.06 6.06 14.01

EXAMPLE 9 Preparation of tablets for oral administration 200 Grams of 2- B[N-(p-chlorocinnamoyl)homopiperazino1-ethyl pyridine hydrochloride were well mixed with 2,000 grams of lactose. The resulting mixture was sifted through a 30 mesh sieve.

Separately, 80 grams of corn starch were kneaded with 300 ml of distilled water to a paste.

The above sifted powdery mixture was well blended with the paste. The resulting blend was again sifted through a 4 mesh sieve to obtain nodules which were dried at the temperature of 50C. for 15 hours. The dried nodules were treated on a granulating machine and then sifted through a 16 mesh sieve.

The resulting granules were coated with a mixture which consists of 30 grams of calcium stearate, 200 grams of corn starch and 80 grams of talc and previously sifted through a 40 mesh sieve. Tablets each containing mg of the said hydrochloride as active ingredient were made of the coated granules.

2-3 Tablets thus obtained may orally be administered 2-3 times a day.

EXAMPLE 10 Preparation of an aqueous solution for injection 100 Grams of 2- B-[N-(p-chlorocinnamoyl)homopiperazino]-ethyl pyridine hydrochloride were dissolved into distilled water specificially prepared for injection. The resulting solution was made up to 5 liters with additional distilled water. With addition of a predetermined quantity of physiological soline, the solution was made isotonic and then filtered through a glass filter. The filtrate was filled in ampoules each containing 10 mg of the active ingredient, sealed and sterilized at 121C. in an autoclave at 15 lbs/in for 25 minutes.

l-2 Ampoules may daily be intravenously injected for therapeutical treatment.

EXAMPLE 1 1 Preparation of liquid for oral administration The concentration of the following formulation was prepared:

pyridine hydrochloride 20.0 grams Purified cane sugar 100.0 grams Glycerol 100.0 ml Synthetic orange essence 0.2 ml Natural orange essence 1.0 ml

The resulting concentrate was diluted with distilled water to make up the total of 1,000 mls. The whole was filtered to obtain the filtrate ready for use.

The liquid medicine thus obtained may orally be administered with shaking 2-4 tea-spoonful a day.

What is claimed is:

l. 2-[B-(N-Acylhomopiperazino)ethyllpyridine represented by the formula wherein R R and R respectively are hydrogen or a substituent selected from the group consisting of halogen, methyl, methoxy, nitro and methane-sulfonyl; and A represents a direct union or vinylene bridge as well as the pharmacologically acceptable acid salts thereof.

2. The compound according to claim 1, namely 2- B-[N-(lll-Chlorobenzoyl)homopiperazino]ethyl} pyridine or its pharmacologically acceptable acid salt.

3. The compound according to claim 1, namely 2- B-[N-(p-Chlorocinnamoyl)homopiperazinoIethyl pyridine or its pharmacologically acceptable acid salt.

4. The compound according to claim 1, namely 2- B-[N-(p-methane-sulfonylbenzoyl)- homopiperazinolethyl}pyridine or its pharmacologically acceptable acid salt.

5. The compound according to claim 1, namely 2- B-[N-(3,S-Dichlorobenzoyl)homopiperazino1ethyl} pyridine or its pharmacologically acceptable acid salt.

6. The compound according to claim 1, namely 2- {B-[N-(tP-Methylbenzoly)homopiperazino1ethyll pyridine or its pharmacologically acceptable acid salt.

7. The compound according to claim 1, namely 2- {fi-[N-(3,4,5-Trimethoxybenzoyl)- 3,755,309 7 8 homopiperazinokthyl}pyridine or its pharmacolog- 9. The compound according to claim 1, namely 2- ically acceptable acid salt. ,G-[N-p-Nitrobenzoyl)homopiperazinojethyll 8. The compound according to claim 1, namely 2- pyridine or its pharmacologically acceptable acid B-[N-(Cinnamoyl)homopiperazino]ethyl pyridine salt.

or its pharmacologically acceptable acid salt. 

2. The compound according to claim 1, namely 2-( Beta -(N-(0-Chlorobenzoyl)homopiperazino)ethyl)pyridine or its pharmacologically acceptable acid salt.
 3. The compound according to claim 1, namely 2-( Beta -(N-(p-Chlorocinnamoyl)homopiperazino)ethyl)pyridine or its pharmacologically acceptable acid salt.
 4. The compound according to claim 1, namely 2-( Beta -(N-(p-methane-sulfonylbenzoyl)homopiperazino)ethyl)pyridine or its pharmacologically acceptable acid salt.
 5. The compound according to claim 1, namely 2-( Beta -(N-(3,5-Dichlorobenzoyl)homopiperazino)ethyl)pyridine or its pharmacologically acceptable acid salt.
 6. The compound according to claim 1, namely 2-( Beta -(N-(0-Methylbenzoly)homopiperazino)ethyl)pyridine or its pharmacologically acceptable acid salt.
 7. The compound according to claim 1, namely 2-( Beta -(N-(3,4, 5-Trimethoxybenzoyl)homopiperazino)ethyl)pyridine or its pharmacologically acceptable acid salt.
 8. The compound according to claim 1, namely 2-( Beta -(N-(Cinnamoyl)homopiperazino)ethyl)pyridine or its pharmacologically acceptable acid salt.
 9. The compound according to claim 1, namely 2-( Beta -(N-''p-Nitrobenzoyl)homopiperazino)ethyl)pyridine or its pharmacologically acceptable acid salt. 